The purpose of the project is to develop a catheter system for interventional radiology which is capable of traversing small and branching blood vessels (i.e. 1.5 to 4.0 mm) to reach the proximity of tumors and to administer chemotherapeutic drugs to these tumors in a controlled manner. A major obstacle to effective treatment is thought to be mal-distribution of the drug at the site due to inadequate mixing with the blood. A multi-lumen micro-catheter, which is propelled and directed through these small blood vessels via jets of fluid emanating from its distal end, has shown promise for negotiating heretofore difficult to reach areas. The catheter is controlled by an adjustable pressurized manifold operated by a joy stick. Provisions for on-line switching from a radiopaque contrast solution to the drug is provided at the manifold. The contrast agent serves as the propelling fluid as well as providing visual identification of the movement and location of the catheter. While fluid turbulence generated at lower pressure by the drug emanating at retrograde angles from the tip of the catheter adds significantly to the mixing of the drug within the blood stream. Animal tests have substantiated the feasibility of the catheter system for clinical use. A transparent model of the vascular network simulating blood flow of a pulsatile nature was designed to evaluate the efficiency of the jet flow at various delivering rates. Surfaces of the catheters have been modified with bonded hydrogels to reduce drag through conventional sheaths and further acts to minimize clotting on the surfaces. A radiopaque marker at the tip of the catheter can be readily located by fluoroscopy.